Stressors during prenatal development may be particularly potent in contributing to an individual's disease vulnerability later in life by affecting the rate of maturation and the establishment of certain immune responses. The goal of this research is to further examine the immunological consequences of gestational experience by evaluating maternal and infant antibody responses to prenatal vaccination under two different prenatal conditions. We propose to measure the passive and active immune responses to prenatal vaccination against Haemophilus influenzae type b (Hib) in pregnant female rhesus monkeys and their infants (Year 1). Once these baseline values are established, females will be subjected to either a psychological stressor paradigm (Year 2) or given moderate levels of alcohol (Year 3) during gestation to test how these factors influence the active immune response to the vaccine in the mother, the placental transfer of anti-Hib antibody to her fetus, and the ability of the infants to mount an active immune response when presented with the vaccine postnatally. We hypothesize that mothers exposed to both disturbance conditions will have a decreased antibody response to the vaccine. Furthermore, while the active placental transfer of antibody may partially compensate for the reductions in maternal antibody, infants born from disturbed pregnancies may have lower antibody levels than those of control infants. Exposure to psychological stress or alcohol prenatally will impair the infant's ability to produce an active antibody response to the vaccine when administered postnatally. Finally, this research will develop the vaccine paradigm as a unique means of assessing the psychobiological well-being of the young infant.